This invention relates generally to a valve for inflatable devices, and particularly, to an easily replaceable valve for an inflatable marine fender. Inflatable pneumatic fenders are typically used to provide a cushion between boat hulls and docks or wharfs to which the boats are tied. Pneumatic fenders are often favored because of their inherent resiliency, and because they prevent marring of boat hull surfaces. Fenders of this type are typically provided with inflation valves for initially inflating the fender, and for periodically replenishing the supply of air to maintain maximum efficiency.
It is often the case, however, that the valve body itself is exposed, i.e., located so as to project above or outside the exterior surface of the fender. As such, the valve assembly is subject to damage from periodic compressive engagement with the dock or wharf, or from relative movement while trapped between the boat hull and the dock or wharf. Damage to the valve assembly can render the fender useless if no provision is made for a protected, and easily replaceable valve assembly which is also airtight.
For example, in U.S. Pat. No. 2,179,125, a typical inflation valve is disclosed which projects outwardly from a lower end surface of an otherwise cylindrical fender body. The valve body is sealed in place to an interior bladder.
In the present invention, a unique valve design is provided which enables the valve to be located at or below the external surface of the fender, while permitting easy inflation of the fender, and easy removal and replacement in the event of damage to the valve. In a preferred embodiment, the valve comprises a flexible hollow tubular member which is open at a first upper end and normally closed at a second lower end, and a collar member threadably receivable within the fender body, and provided with a centrally located bore which is adapted to receive the upper portion of the flexible hollow tubular member. The flexible member is formed with a radially outwardly extending flange intermediate its first and second ends for seating engagement with a complimentary surface provided in a valve seat integrally formed in the fender body. The collar member has a lower surface which engages the radially outwardly directed flange provided on the flexible valve member. In the event of damage to the valve structure, the collar member is merely unscrewed from the fender body, permitting the flexible member to be slidably removed from the fender and easily replaced.
The valve as described, and when installed in a fender, can be used with a conventional needle valve to inflate the fender.
An additional advantage of the present invention is that the valve can be removed to allow rapid inflation of the device with a compressed air system.
Moreover, in the event that it is desirable to replace the valve of this invention with a different type, e.g., a one-piece rigid plug, the valve is easily removed to facilitate such replacement.
The normally closed end of the flexible valve member is provided with a slit adapted to be opened by the insertion of a conventional needle valve in a manner which will be well understood by those of ordinary skill in the art. The flexible member is preferably constructed of an elastomer such as nitrile, thermoplastic rubber, or natural rubber to provide sufficient resiliency so that upon removal of a needle valve, the slit in the normally closed end of the flexible member will close on itself and prevent escape of air from within the fender.
The collar member is preferably constructed of a rigid thermoplastic material such as nylon or nylon alloy, lexan, polycarbonate, or other suitable material.
In an exemplary embodiment of the invention, the upper portion of the collar member is provided with an enlarged head formed with tool engaging means, such as a screwdriver slot, to facilitate easy removal of the collar member and flexible member from the fender.
In an alternative arrangement, the collar and flexible members may be mechanically joined to further facilitate removal and installation of the valve. For example, the flexible member may be friction fit within the collar, or a snap-fit configuration may be provided. The collar and flexible members may also be adhesively joined.
It will be appreciated that the valve seat that receives the flexible member and the collar member may be molded into the fender body itself as an integral unit, or be a separately molded piece that is subsequently molded into the fender body. The valve seat is preferably made of flexible PVC, 40 to 90 durometer, on the shore A scale.
It will also be understood that the valve as described above may be of other multiple piece designs, i.e., where the collar member extends full length of the flexible member, or may also be of molded one-piece construction, i.e., where the collar and flexible members are formed as an integral valve which may be threadably mounted in the valve seat.
Other objects and advantages of the invention will become apparent upon further inspection of the detailed description of the invention which follows.